Since they began play at Citi Field, the Mets have a .731 O.P.S. at home, .704 on the road. That is an O.P.S. advantage of 27 points, compared with 37 for the National League over all. That is a negligible difference, largely caused by the recent offensive woes. (Take out the previous homestand, and the Mets’ advantage is virtually identical to that of the league.)
But Mets pitchers have a huge edge over the typical advantage pitchers have at home. From 2009-11, Mets pitchers have allowed a . 696 O.P.S. at Citi Field and a .788 O.P.S. on the road. That is a 92-point advantage, compared with 42 points for that of the league. The Mets pitchers’ 50-point O.P.S. advantage is greater than the difference between Ben Zobrist’s good 2011 season for Tampa Bay and Jose Reyes’s great one for the Mets.
Any changes to, say, the outfield walls would affect both the offense and pitching at Citi Field. But the current setup appears to have little to no effect on the Mets’ offense, while providing a huge advantage to the pitching staff.
Statistically, the Mets have a marked home-field advantage. But if they want more offense, they need to field a better offensive team.